Hardware Update Logs

Update Log for ESP Relay Board

Update R1.6

Optmized lead out pins, IO4, IO5 used for IIC bus, see the demo image here.

Updated R1.5:

Optimized board layout, replace a few higher quality parts

Updated version R1.1:

Fix isolation and current drop issue on old version, which cause the ESP-wifi board may have a 5% chance to reset/restart when you switch relays On/Off very very frequently. R1.1 version is not absolutely can be eliminated this issue since the onboard AC-DC module has a limit, but the probability of this problem should be controlled to the least, low to one percent.

Maximum trace design for current passing, 2MM trace width to let 2A current pass through roughly for two relays together, so either 2A for running one channel device or 1A for two device. also open trace without soldermask, you can add more solders to get even higher current passing.

Update Log for ESP Relay Board VDC

V4.2 added voltage divider on back side of PCB, this need to be soldered manually.

V4.1 pin headers changed to two group. RST, ADC and DHT_IO16 pins on left side now.

Use of AC Main Power IN to Relay

to switch to control AC mains power, need to remove two 1206 0R resistors on board. Then power from left green terminal = relay output (and terminal)

To supply power on board control circuit, add 6-24V power to "ALT VIN" pins

Add-Ons Functions

IO4 and IO5

IO4 and IO5 hs pull up resistors for IIC bus to use

Demo code for IIC OLED screen for LUA can be found at nodemcu github, /master/lua_examples/u8glib/ this folder, or click here to browse.

To remove the pull-up resistor, find the 2x two-very-close-pin on the right side of break away header pin 4 and pin 5, use knife to cut them, then 4.7K resistor will be disconnected. Also can add solder to re-connect them later.

DHT Sensor

Please connect the board to sensor by wires, because the PCB and relays will generate heats!!

DHT22 support plug on to use, feel free to use wires or socket to settle the DHT sensor, pin definition is 3V3, data, NC and GND